This filter was found in an American publication from the 1980s. The circuit can be implemented with any operational amplifier. The power supply must be symmetrical.
This circuit was obtained in an old Argentine publication, using germanium transistors and...
This very low resistance meter was found in the February 1995 issue of Electronics Now magazine. The...
Using a CA3130 operational amplifier, this circuit was found in an English publication from 1977....